GOP presidential candidate Herman Cain is taking heat for yet another love affair allegation, leading to rumors that this could be the final blow that defeats the former businessman and lobbyist's candidacy. However, whatever one might think of Cain's political ideas or his personal life, if history is any kind of indicator, extramarital affairs appear to come with the territory of being the president of the United States, dating all the way back to George Washington.

George Washington and Thomas Jefferson have more in common than them both being signers of the Constitution -- they have also both been accused of fathering children with their own slaves. Jefferson's case is well known and many books and a few movies have portrayed his relationship with Sally Hemings, a slave who lived on his Monticello ranch. In 1988, DNA evidence gave new thrust to beliefs that Jefferson indeed fathered Heming's children.

Washington's case is less well known. There is no reliable DNA evidence to test, but descendants of a slave named West Ford claim that oral histories indicate that the nation's first president fathered a child with a slave named Venus.

In a 1998 program on PBS titled "George & Venus," descendants and historians argue over the validity of the claims that Washington fathered a child with a slave. The primary evidence is the apparent physical characteristics Ford shared with Washington, as well as the preferential treatment that Venus and Ford were given by Washington and his family, including allowing Ford to be educated with the children in Washington's family and later being left a large plot of land after the passing of a Washington relative.

However, Venus was actually Washington's brother's slave, which have led some historians to believe that one of Washington's relatives, either a brother or nephew, was the real father of Ford. Whatever the case is, the issue was kept quiet at the time and will likely never be answered.

Washington's case is far different from what Thomas Jefferson experienced, which was a sort of foreshadowing of what happens today when a politician is suspected of adultery -- his opponents try to capitalize off of it.

According to the website of Jefferson's historical Monticello ranch, the third president of the U.S. was accused of having an affair with a slave during his first term in office in September 1802, when political journalist James T. Callendar wrote in a Richmond newspaper that Jefferson had "kept, as his concubine, one of his own slaves...Her name is Sally," adding that Jefferson had "several children" by her.

Jefferson did not respond to the allegations, and they appear to have had very little, if any impact on his presidency. But the rumors persisted and have lived on, inspiring numerous accounts in books and films. In 1998, DNA tests proved that at least one of Heming's children carried genes from Jefferson's family and the study's authors said that "the simplest and most probable" conclusion was that Thomas Jefferson was the father.

In more recent times, there seems to be more presidents who have had extramarital affairs than presidents who did not.

Warren G. Harding is rumored to have had at least two, long-term affairs with women outside his marriage, including with family friend, Nan Britton, who wrote a tell-all about her alleged affair with the 29th president after his death. The book is considered the first political "kiss-and-tell."

Franklin D. Roosevelt, despite being confined to a wheelchair for much of his presidency, did not let his handicaps keep him from an alleged long-term affair with Lucy Page Mercer Rutherfud, which began when the future father of the New Deal was the Assistant Secretary of the U.S. Navy in 1913. The relationship allegedly lasted for several more years, including throughout Roosevelt's presidency.

President Dwight D. Eisenhower, the former army general, is said to have had an affair with Kay Summersby, a Britain-born member of the military who met "Ike" as a driver in the Mechanised Transport Corps. The two had a three0year love affair between 1942-1945, according to Past Forgetting: My Love Affair with Dwight D. Eisenhower, a book Summersby wrote about the relationship.

Both John F. Kennedy and Lyndon B. Johnson had well-known affairs, although both men were able to keep them from becoming a point of interest during their presidencies, despite JFK allegedly having affairs with several world-famous movie stars, including Marilyn Monroe and Marlene Dietrich.

However, after LBJ and up until Bill Clinton's presidency, American presidents appeared to have been loyal to their wives. There are no accounts of Richard Nixon, Gerald Ford, Jimmy Carter, Ronald Reagan, or George H.W. Bush having extra-marital affairs.

Also, since Clinton, presidents George W. Bush and Barack Obama appear to be not guilty of ever breaking the seventh commandment.

However, if Obama loses the presidency in 2012 to either Cain or Newt Gingrich, histories of adultery could be back in the White House. Although Cain has denied every accusation on infidelity leveled against him, Gingrich has admitted that he was cheating on his wife at the same time he was leading the way to impeach Clinton for lying about his affair with Monica Lewinsky under oath. Clinton was later acquitted.

"The honest answer is yes," Gingrich said in an interview with Focus on the Family founder James Dobson in 2009 when asked if he had an affair during the Clinton impeachment trials, according to CBS News. "There are times that I have fallen short of my own standards. There's certainly times when I've fallen short of God's standards."

Cain, who gave CNN reporter Wolf Blitz a "heads up" Monday about the most recent allegation from an Atlanta woman who claims she and the businessman had an affair for 13 years, revealed Tuesday that he is "reassessing" his campaign strategy.

The Atlanta businessman has said before that if the storm surrounding the allegations of infidelity prove too much for his family, then he would consider closing the door on his pursuit of the presidency.